Cased Image Project at the Chicago History Museum
"The Case of the Fading Photographs"
Taken from the "Past Times" Newsletter of the Chicago Historical Society
In a quiet storage area at the Chicago Historical Society (CHS), a bit of history was in danger of being lost forever. many of the CHS's collection of rare, early photographs, known as "cased images" because of their elaborate cases, were deteriorating due to age, use, and the inevitable breakdown of original materials.
Cased images, typically portraits, were produced from 1839 - the year photography was invented - to around 1879. Photographers used now - obsolete processes to create a variety of photographic images: daguerreotypes in the earliest years, then ambrotypes, and finally tintypes. These images were displayed behind glass in small, hinged cases, which protected the photographs, made them portable, and imitated the look of the more expensive painted miniature portrait.
The nearly one thousand cased images owned by CHS record the early history of Chicago and the United States. The collection is nationally renowned for its portraits of prominent figures such as Daniel Webster, Lucretia Mott, and Sam Houston. Equally important, the collection includes portraits of a diverse array of Chicagoans, from founding families of the city to unidentified Civil War soldiers in uniform.
In 1996, the Chicago Historical Society began a multifacited project to preserve these valuable artifacts and to make them more accessible to researchers. Funds for the project were donated by the Chicago photographic Collectors Society (CPCS), a nonprofit organization dedicated to the preservation and care of antique photographs and photographic equipment. "Last year was our twenty-fifth anniversary and we wanted to mark it by funding something that would benefit the public," says Kirk Kekatos of the CPCS. "I contacted (CHS's former curator of prints and photographs,) Larry Viskochil, and he suggested this project."
Many of the cased images are in danger because the nineteenth century glass covering or supporting each photograph is deteriorating, often obscuring the image as well as releasing damaging substances onto its surface. To prepare the images to be photographed, CHS conservator Carol Turchan and her assistant, Bozena Pszczulna Sxmanski, painstakingly disassembled each case and cleaned the old glass.
Next, photographers took digital pictures of the cased images, which they stored on photo CD's. By the end of this year, these digital photographs will be added to a database so that researchers visiting CHS can view each cased image on a computer screen. This method of viewing the images will dramatically reduce unnecessary handling of the original objects, further helping to preserve them.
The current phase of the project involves extensive conservation of the most endangered items. Conservators are replacing original glass with modern glass and are using a method called electrocleaning to remove silver tarnish, residues caused by previous cleaning methods, and deposits left by deteriorating glass.
CPCS members visit CHS's paper conservation lab to review
progress of the cased image project, 1996.
Photograph by Martin J. Schmidt
The Chicago Historical Society is grateful to the Chicago Photographic Collectors Society for their many years of support and their generous underwriting of this project, which will ensure a richer visual history for future generations.
Reproduced with permission of the Chicago Historical Society
Chicago Photographic Collectors Society Members visit the Chicago Historical Society's Paper and Photograph Conservation Laboratory for an update on the cased photograph preservation and access project.
Carol Turchan, CHS Conservator discussing procedures used to preserve different types of cased photographs.CPCS Members examining cased photographs in various stages of treatment.
CPCS Board ember Kirk Kekatos examines deteriorating Ambrotype under the microscope. CPCS Membership Secretary Anne Kekatos views work in progress.
Ambrotype portrait that shows an unusual form of deterioration.
Ambrotype view of a residence showing effects of glass deterioration. Ambrotypes must me copied to preserve images before collodion emulsions are severely damaged by the glass.
A wet plate glass negative becomes a positive Ambrotype image when a black backing is provided. The backing may be varnish, paper, cloth or black pigment on a metal plate.
Deteriorated cover glasses removed from Daguerreotypes, and a backing plate removed from behind an Ambrotype which shows an unidentified white residue.
Detail of the black painted metal plate with white residue from the deteriorating Ambrotype.
Two identical Daguerreotypes (although the process yields only one photograph per sitting). The top image has been electro-cleaned, and the bottom image is still severely tarnished, or oxidized.
Pre-fire (1871) Ambrotype view of Phillips Chair Factory (G1985.041). This plate is still in good condition, awaiting duplication.
Ambrotype of Julia Holnus by Mathew Brady. The image is visible in its case from both sides. the case has been repaired to support the additional weight of two brass mats, preservers and cover glasses.
Tintype "gem" class pictures, each about 1" in height.